宁夏牧区主要绵羊品种遗传多样性分析及群体间杂种优势预测

Genetic Polymorphic Analysis and Forecast of Heterosis of Sheep in Ningxia Autonomous Region

利用7个微卫星标记对宁夏牧区陶赛特、得克赛尔、萨福克、滩羊、小尾寒羊、滩寒杂种羊6个绵羊群体进行遗传多样性检测,并根据遗传距离对群体间杂种优势进行预测,结果显示:6个绵羊群体共检测到108个等位基因,每个座位在每个群体都检测到5个以上等位基因,7个微卫星座位在6个群体中呈高度多态性,期望杂合度远大于观测杂合度,群体间表型分化系数(Fst)较低,为5.8%,与Gst结果基本一致,总群体近交系数(Fit)为56.90%,群体内近交系数(Fis)为54.36%。根据DC遗传距离和DA遗传距离,预测群体间杂种优势,杂交母本品种以滩寒杂种羊效果最好,滩羊次之,小尾寒羊最差;杂交父本的选择顺序为得克赛尔、萨福克、陶赛特。

The genomes of six populations （Dorset, Texel, Black-Suffolk, Tan sheep, Small-tailed Han sheep, hybrid of Tan and Small-tailed Han sheep） were screened with 7 microsatellite loci, and genetic diversities and genetic distance were estimated in this study. The results showed that, 108 alleles were detected in six populations, all the loci showed polymorphism in each population. The expected heterozygosity of all populations were much higher than the observed heterozygosity. The coefficient of phenotype differentiation （Fst） between populations was very low, the value was 5.8%, which was consistent with the coefficient of gene differentiation （Gst）. The inbreeding coefficients for all populations （Fit） amounted to 56. 90%. The inbreeding coefficients within breeds （Fis） was 54.36%. The heterosis between populations was also forecast according to DC distance and Nei＇s genetic distance （DA）, hybrid with Tan and small-tailed Han sheep as female parent was the best, then was Tan sheep, and Small-tailed Han sheep was the worst. The selective order for male parent should be Texel, Black-Suffolk, and then Dorset concerned with hybrid effects.